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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network143.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
143.0.0.0
Broadcast address
143.255.255.255
First usable
143.0.0.1
Last usable
143.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
B (default /16)
As numbers
Hex 8F000000 · Integer 2399141888 to 2415919103
Reverse DNS zone
143.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001111..00000000.00000000.00000000143.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001111..00000000.00000000.00000000143.0.0.0
Broadcast10001111..11111111.11111111.11111111143.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

143.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1143.0.0.0/16143.0.0.1 to 143.0.255.254143.0.255.25565,534
2143.1.0.0/16143.1.0.1 to 143.1.255.254143.1.255.25565,534
3143.2.0.0/16143.2.0.1 to 143.2.255.254143.2.255.25565,534
4143.3.0.0/16143.3.0.1 to 143.3.255.254143.3.255.25565,534
5143.4.0.0/16143.4.0.1 to 143.4.255.254143.4.255.25565,534
6143.5.0.0/16143.5.0.1 to 143.5.255.254143.5.255.25565,534
7143.6.0.0/16143.6.0.1 to 143.6.255.254143.6.255.25565,534
8143.7.0.0/16143.7.0.1 to 143.7.255.254143.7.255.25565,534
9143.8.0.0/16143.8.0.1 to 143.8.255.254143.8.255.25565,534
10143.9.0.0/16143.9.0.1 to 143.9.255.254143.9.255.25565,534
11143.10.0.0/16143.10.0.1 to 143.10.255.254143.10.255.25565,534
12143.11.0.0/16143.11.0.1 to 143.11.255.254143.11.255.25565,534
13143.12.0.0/16143.12.0.1 to 143.12.255.254143.12.255.25565,534
14143.13.0.0/16143.13.0.1 to 143.13.255.254143.13.255.25565,534
15143.14.0.0/16143.14.0.1 to 143.14.255.254143.14.255.25565,534
16143.15.0.0/16143.15.0.1 to 143.15.255.254143.15.255.25565,534
17143.16.0.0/16143.16.0.1 to 143.16.255.254143.16.255.25565,534
18143.17.0.0/16143.17.0.1 to 143.17.255.254143.17.255.25565,534
19143.18.0.0/16143.18.0.1 to 143.18.255.254143.18.255.25565,534
20143.19.0.0/16143.19.0.1 to 143.19.255.254143.19.255.25565,534
21143.20.0.0/16143.20.0.1 to 143.20.255.254143.20.255.25565,534
22143.21.0.0/16143.21.0.1 to 143.21.255.254143.21.255.25565,534
23143.22.0.0/16143.22.0.1 to 143.22.255.254143.22.255.25565,534
24143.23.0.0/16143.23.0.1 to 143.23.255.254143.23.255.25565,534
25143.24.0.0/16143.24.0.1 to 143.24.255.254143.24.255.25565,534
26143.25.0.0/16143.25.0.1 to 143.25.255.254143.25.255.25565,534
27143.26.0.0/16143.26.0.1 to 143.26.255.254143.26.255.25565,534
28143.27.0.0/16143.27.0.1 to 143.27.255.254143.27.255.25565,534
29143.28.0.0/16143.28.0.1 to 143.28.255.254143.28.255.25565,534
30143.29.0.0/16143.29.0.1 to 143.29.255.254143.29.255.25565,534
31143.30.0.0/16143.30.0.1 to 143.30.255.254143.30.255.25565,534
32143.31.0.0/16143.31.0.1 to 143.31.255.254143.31.255.25565,534
33143.32.0.0/16143.32.0.1 to 143.32.255.254143.32.255.25565,534
34143.33.0.0/16143.33.0.1 to 143.33.255.254143.33.255.25565,534
35143.34.0.0/16143.34.0.1 to 143.34.255.254143.34.255.25565,534
36143.35.0.0/16143.35.0.1 to 143.35.255.254143.35.255.25565,534
37143.36.0.0/16143.36.0.1 to 143.36.255.254143.36.255.25565,534
38143.37.0.0/16143.37.0.1 to 143.37.255.254143.37.255.25565,534
39143.38.0.0/16143.38.0.1 to 143.38.255.254143.38.255.25565,534
40143.39.0.0/16143.39.0.1 to 143.39.255.254143.39.255.25565,534
41143.40.0.0/16143.40.0.1 to 143.40.255.254143.40.255.25565,534
42143.41.0.0/16143.41.0.1 to 143.41.255.254143.41.255.25565,534
43143.42.0.0/16143.42.0.1 to 143.42.255.254143.42.255.25565,534
44143.43.0.0/16143.43.0.1 to 143.43.255.254143.43.255.25565,534
45143.44.0.0/16143.44.0.1 to 143.44.255.254143.44.255.25565,534
46143.45.0.0/16143.45.0.1 to 143.45.255.254143.45.255.25565,534
47143.46.0.0/16143.46.0.1 to 143.46.255.254143.46.255.25565,534
48143.47.0.0/16143.47.0.1 to 143.47.255.254143.47.255.25565,534
49143.48.0.0/16143.48.0.1 to 143.48.255.254143.48.255.25565,534
50143.49.0.0/16143.49.0.1 to 143.49.255.254143.49.255.25565,534
51143.50.0.0/16143.50.0.1 to 143.50.255.254143.50.255.25565,534
52143.51.0.0/16143.51.0.1 to 143.51.255.254143.51.255.25565,534
53143.52.0.0/16143.52.0.1 to 143.52.255.254143.52.255.25565,534
54143.53.0.0/16143.53.0.1 to 143.53.255.254143.53.255.25565,534
55143.54.0.0/16143.54.0.1 to 143.54.255.254143.54.255.25565,534
56143.55.0.0/16143.55.0.1 to 143.55.255.254143.55.255.25565,534
57143.56.0.0/16143.56.0.1 to 143.56.255.254143.56.255.25565,534
58143.57.0.0/16143.57.0.1 to 143.57.255.254143.57.255.25565,534
59143.58.0.0/16143.58.0.1 to 143.58.255.254143.58.255.25565,534
60143.59.0.0/16143.59.0.1 to 143.59.255.254143.59.255.25565,534
61143.60.0.0/16143.60.0.1 to 143.60.255.254143.60.255.25565,534
62143.61.0.0/16143.61.0.1 to 143.61.255.254143.61.255.25565,534
63143.62.0.0/16143.62.0.1 to 143.62.255.254143.62.255.25565,534
64143.63.0.0/16143.63.0.1 to 143.63.255.254143.63.255.25565,534
65143.64.0.0/16143.64.0.1 to 143.64.255.254143.64.255.25565,534
66143.65.0.0/16143.65.0.1 to 143.65.255.254143.65.255.25565,534
67143.66.0.0/16143.66.0.1 to 143.66.255.254143.66.255.25565,534
68143.67.0.0/16143.67.0.1 to 143.67.255.254143.67.255.25565,534
69143.68.0.0/16143.68.0.1 to 143.68.255.254143.68.255.25565,534
70143.69.0.0/16143.69.0.1 to 143.69.255.254143.69.255.25565,534
71143.70.0.0/16143.70.0.1 to 143.70.255.254143.70.255.25565,534
72143.71.0.0/16143.71.0.1 to 143.71.255.254143.71.255.25565,534
73143.72.0.0/16143.72.0.1 to 143.72.255.254143.72.255.25565,534
74143.73.0.0/16143.73.0.1 to 143.73.255.254143.73.255.25565,534
75143.74.0.0/16143.74.0.1 to 143.74.255.254143.74.255.25565,534
76143.75.0.0/16143.75.0.1 to 143.75.255.254143.75.255.25565,534
77143.76.0.0/16143.76.0.1 to 143.76.255.254143.76.255.25565,534
78143.77.0.0/16143.77.0.1 to 143.77.255.254143.77.255.25565,534
79143.78.0.0/16143.78.0.1 to 143.78.255.254143.78.255.25565,534
80143.79.0.0/16143.79.0.1 to 143.79.255.254143.79.255.25565,534
81143.80.0.0/16143.80.0.1 to 143.80.255.254143.80.255.25565,534
82143.81.0.0/16143.81.0.1 to 143.81.255.254143.81.255.25565,534
83143.82.0.0/16143.82.0.1 to 143.82.255.254143.82.255.25565,534
84143.83.0.0/16143.83.0.1 to 143.83.255.254143.83.255.25565,534
85143.84.0.0/16143.84.0.1 to 143.84.255.254143.84.255.25565,534
86143.85.0.0/16143.85.0.1 to 143.85.255.254143.85.255.25565,534
87143.86.0.0/16143.86.0.1 to 143.86.255.254143.86.255.25565,534
88143.87.0.0/16143.87.0.1 to 143.87.255.254143.87.255.25565,534
89143.88.0.0/16143.88.0.1 to 143.88.255.254143.88.255.25565,534
90143.89.0.0/16143.89.0.1 to 143.89.255.254143.89.255.25565,534
91143.90.0.0/16143.90.0.1 to 143.90.255.254143.90.255.25565,534
92143.91.0.0/16143.91.0.1 to 143.91.255.254143.91.255.25565,534
93143.92.0.0/16143.92.0.1 to 143.92.255.254143.92.255.25565,534
94143.93.0.0/16143.93.0.1 to 143.93.255.254143.93.255.25565,534
95143.94.0.0/16143.94.0.1 to 143.94.255.254143.94.255.25565,534
96143.95.0.0/16143.95.0.1 to 143.95.255.254143.95.255.25565,534
97143.96.0.0/16143.96.0.1 to 143.96.255.254143.96.255.25565,534
98143.97.0.0/16143.97.0.1 to 143.97.255.254143.97.255.25565,534
99143.98.0.0/16143.98.0.1 to 143.98.255.254143.98.255.25565,534
100143.99.0.0/16143.99.0.1 to 143.99.255.254143.99.255.25565,534
101143.100.0.0/16143.100.0.1 to 143.100.255.254143.100.255.25565,534
102143.101.0.0/16143.101.0.1 to 143.101.255.254143.101.255.25565,534
103143.102.0.0/16143.102.0.1 to 143.102.255.254143.102.255.25565,534
104143.103.0.0/16143.103.0.1 to 143.103.255.254143.103.255.25565,534
105143.104.0.0/16143.104.0.1 to 143.104.255.254143.104.255.25565,534
106143.105.0.0/16143.105.0.1 to 143.105.255.254143.105.255.25565,534
107143.106.0.0/16143.106.0.1 to 143.106.255.254143.106.255.25565,534
108143.107.0.0/16143.107.0.1 to 143.107.255.254143.107.255.25565,534
109143.108.0.0/16143.108.0.1 to 143.108.255.254143.108.255.25565,534
110143.109.0.0/16143.109.0.1 to 143.109.255.254143.109.255.25565,534
111143.110.0.0/16143.110.0.1 to 143.110.255.254143.110.255.25565,534
112143.111.0.0/16143.111.0.1 to 143.111.255.254143.111.255.25565,534
113143.112.0.0/16143.112.0.1 to 143.112.255.254143.112.255.25565,534
114143.113.0.0/16143.113.0.1 to 143.113.255.254143.113.255.25565,534
115143.114.0.0/16143.114.0.1 to 143.114.255.254143.114.255.25565,534
116143.115.0.0/16143.115.0.1 to 143.115.255.254143.115.255.25565,534
117143.116.0.0/16143.116.0.1 to 143.116.255.254143.116.255.25565,534
118143.117.0.0/16143.117.0.1 to 143.117.255.254143.117.255.25565,534
119143.118.0.0/16143.118.0.1 to 143.118.255.254143.118.255.25565,534
120143.119.0.0/16143.119.0.1 to 143.119.255.254143.119.255.25565,534
121143.120.0.0/16143.120.0.1 to 143.120.255.254143.120.255.25565,534
122143.121.0.0/16143.121.0.1 to 143.121.255.254143.121.255.25565,534
123143.122.0.0/16143.122.0.1 to 143.122.255.254143.122.255.25565,534
124143.123.0.0/16143.123.0.1 to 143.123.255.254143.123.255.25565,534
125143.124.0.0/16143.124.0.1 to 143.124.255.254143.124.255.25565,534
126143.125.0.0/16143.125.0.1 to 143.125.255.254143.125.255.25565,534
127143.126.0.0/16143.126.0.1 to 143.126.255.254143.126.255.25565,534
128143.127.0.0/16143.127.0.1 to 143.127.255.254143.127.255.25565,534
129143.128.0.0/16143.128.0.1 to 143.128.255.254143.128.255.25565,534
130143.129.0.0/16143.129.0.1 to 143.129.255.254143.129.255.25565,534
131143.130.0.0/16143.130.0.1 to 143.130.255.254143.130.255.25565,534
132143.131.0.0/16143.131.0.1 to 143.131.255.254143.131.255.25565,534
133143.132.0.0/16143.132.0.1 to 143.132.255.254143.132.255.25565,534
134143.133.0.0/16143.133.0.1 to 143.133.255.254143.133.255.25565,534
135143.134.0.0/16143.134.0.1 to 143.134.255.254143.134.255.25565,534
136143.135.0.0/16143.135.0.1 to 143.135.255.254143.135.255.25565,534
137143.136.0.0/16143.136.0.1 to 143.136.255.254143.136.255.25565,534
138143.137.0.0/16143.137.0.1 to 143.137.255.254143.137.255.25565,534
139143.138.0.0/16143.138.0.1 to 143.138.255.254143.138.255.25565,534
140143.139.0.0/16143.139.0.1 to 143.139.255.254143.139.255.25565,534
141143.140.0.0/16143.140.0.1 to 143.140.255.254143.140.255.25565,534
142143.141.0.0/16143.141.0.1 to 143.141.255.254143.141.255.25565,534
143143.142.0.0/16143.142.0.1 to 143.142.255.254143.142.255.25565,534
144143.143.0.0/16143.143.0.1 to 143.143.255.254143.143.255.25565,534
145143.144.0.0/16143.144.0.1 to 143.144.255.254143.144.255.25565,534
146143.145.0.0/16143.145.0.1 to 143.145.255.254143.145.255.25565,534
147143.146.0.0/16143.146.0.1 to 143.146.255.254143.146.255.25565,534
148143.147.0.0/16143.147.0.1 to 143.147.255.254143.147.255.25565,534
149143.148.0.0/16143.148.0.1 to 143.148.255.254143.148.255.25565,534
150143.149.0.0/16143.149.0.1 to 143.149.255.254143.149.255.25565,534
151143.150.0.0/16143.150.0.1 to 143.150.255.254143.150.255.25565,534
152143.151.0.0/16143.151.0.1 to 143.151.255.254143.151.255.25565,534
153143.152.0.0/16143.152.0.1 to 143.152.255.254143.152.255.25565,534
154143.153.0.0/16143.153.0.1 to 143.153.255.254143.153.255.25565,534
155143.154.0.0/16143.154.0.1 to 143.154.255.254143.154.255.25565,534
156143.155.0.0/16143.155.0.1 to 143.155.255.254143.155.255.25565,534
157143.156.0.0/16143.156.0.1 to 143.156.255.254143.156.255.25565,534
158143.157.0.0/16143.157.0.1 to 143.157.255.254143.157.255.25565,534
159143.158.0.0/16143.158.0.1 to 143.158.255.254143.158.255.25565,534
160143.159.0.0/16143.159.0.1 to 143.159.255.254143.159.255.25565,534
161143.160.0.0/16143.160.0.1 to 143.160.255.254143.160.255.25565,534
162143.161.0.0/16143.161.0.1 to 143.161.255.254143.161.255.25565,534
163143.162.0.0/16143.162.0.1 to 143.162.255.254143.162.255.25565,534
164143.163.0.0/16143.163.0.1 to 143.163.255.254143.163.255.25565,534
165143.164.0.0/16143.164.0.1 to 143.164.255.254143.164.255.25565,534
166143.165.0.0/16143.165.0.1 to 143.165.255.254143.165.255.25565,534
167143.166.0.0/16143.166.0.1 to 143.166.255.254143.166.255.25565,534
168143.167.0.0/16143.167.0.1 to 143.167.255.254143.167.255.25565,534
169143.168.0.0/16143.168.0.1 to 143.168.255.254143.168.255.25565,534
170143.169.0.0/16143.169.0.1 to 143.169.255.254143.169.255.25565,534
171143.170.0.0/16143.170.0.1 to 143.170.255.254143.170.255.25565,534
172143.171.0.0/16143.171.0.1 to 143.171.255.254143.171.255.25565,534
173143.172.0.0/16143.172.0.1 to 143.172.255.254143.172.255.25565,534
174143.173.0.0/16143.173.0.1 to 143.173.255.254143.173.255.25565,534
175143.174.0.0/16143.174.0.1 to 143.174.255.254143.174.255.25565,534
176143.175.0.0/16143.175.0.1 to 143.175.255.254143.175.255.25565,534
177143.176.0.0/16143.176.0.1 to 143.176.255.254143.176.255.25565,534
178143.177.0.0/16143.177.0.1 to 143.177.255.254143.177.255.25565,534
179143.178.0.0/16143.178.0.1 to 143.178.255.254143.178.255.25565,534
180143.179.0.0/16143.179.0.1 to 143.179.255.254143.179.255.25565,534
181143.180.0.0/16143.180.0.1 to 143.180.255.254143.180.255.25565,534
182143.181.0.0/16143.181.0.1 to 143.181.255.254143.181.255.25565,534
183143.182.0.0/16143.182.0.1 to 143.182.255.254143.182.255.25565,534
184143.183.0.0/16143.183.0.1 to 143.183.255.254143.183.255.25565,534
185143.184.0.0/16143.184.0.1 to 143.184.255.254143.184.255.25565,534
186143.185.0.0/16143.185.0.1 to 143.185.255.254143.185.255.25565,534
187143.186.0.0/16143.186.0.1 to 143.186.255.254143.186.255.25565,534
188143.187.0.0/16143.187.0.1 to 143.187.255.254143.187.255.25565,534
189143.188.0.0/16143.188.0.1 to 143.188.255.254143.188.255.25565,534
190143.189.0.0/16143.189.0.1 to 143.189.255.254143.189.255.25565,534
191143.190.0.0/16143.190.0.1 to 143.190.255.254143.190.255.25565,534
192143.191.0.0/16143.191.0.1 to 143.191.255.254143.191.255.25565,534
193143.192.0.0/16143.192.0.1 to 143.192.255.254143.192.255.25565,534
194143.193.0.0/16143.193.0.1 to 143.193.255.254143.193.255.25565,534
195143.194.0.0/16143.194.0.1 to 143.194.255.254143.194.255.25565,534
196143.195.0.0/16143.195.0.1 to 143.195.255.254143.195.255.25565,534
197143.196.0.0/16143.196.0.1 to 143.196.255.254143.196.255.25565,534
198143.197.0.0/16143.197.0.1 to 143.197.255.254143.197.255.25565,534
199143.198.0.0/16143.198.0.1 to 143.198.255.254143.198.255.25565,534
200143.199.0.0/16143.199.0.1 to 143.199.255.254143.199.255.25565,534
201143.200.0.0/16143.200.0.1 to 143.200.255.254143.200.255.25565,534
202143.201.0.0/16143.201.0.1 to 143.201.255.254143.201.255.25565,534
203143.202.0.0/16143.202.0.1 to 143.202.255.254143.202.255.25565,534
204143.203.0.0/16143.203.0.1 to 143.203.255.254143.203.255.25565,534
205143.204.0.0/16143.204.0.1 to 143.204.255.254143.204.255.25565,534
206143.205.0.0/16143.205.0.1 to 143.205.255.254143.205.255.25565,534
207143.206.0.0/16143.206.0.1 to 143.206.255.254143.206.255.25565,534
208143.207.0.0/16143.207.0.1 to 143.207.255.254143.207.255.25565,534
209143.208.0.0/16143.208.0.1 to 143.208.255.254143.208.255.25565,534
210143.209.0.0/16143.209.0.1 to 143.209.255.254143.209.255.25565,534
211143.210.0.0/16143.210.0.1 to 143.210.255.254143.210.255.25565,534
212143.211.0.0/16143.211.0.1 to 143.211.255.254143.211.255.25565,534
213143.212.0.0/16143.212.0.1 to 143.212.255.254143.212.255.25565,534
214143.213.0.0/16143.213.0.1 to 143.213.255.254143.213.255.25565,534
215143.214.0.0/16143.214.0.1 to 143.214.255.254143.214.255.25565,534
216143.215.0.0/16143.215.0.1 to 143.215.255.254143.215.255.25565,534
217143.216.0.0/16143.216.0.1 to 143.216.255.254143.216.255.25565,534
218143.217.0.0/16143.217.0.1 to 143.217.255.254143.217.255.25565,534
219143.218.0.0/16143.218.0.1 to 143.218.255.254143.218.255.25565,534
220143.219.0.0/16143.219.0.1 to 143.219.255.254143.219.255.25565,534
221143.220.0.0/16143.220.0.1 to 143.220.255.254143.220.255.25565,534
222143.221.0.0/16143.221.0.1 to 143.221.255.254143.221.255.25565,534
223143.222.0.0/16143.222.0.1 to 143.222.255.254143.222.255.25565,534
224143.223.0.0/16143.223.0.1 to 143.223.255.254143.223.255.25565,534
225143.224.0.0/16143.224.0.1 to 143.224.255.254143.224.255.25565,534
226143.225.0.0/16143.225.0.1 to 143.225.255.254143.225.255.25565,534
227143.226.0.0/16143.226.0.1 to 143.226.255.254143.226.255.25565,534
228143.227.0.0/16143.227.0.1 to 143.227.255.254143.227.255.25565,534
229143.228.0.0/16143.228.0.1 to 143.228.255.254143.228.255.25565,534
230143.229.0.0/16143.229.0.1 to 143.229.255.254143.229.255.25565,534
231143.230.0.0/16143.230.0.1 to 143.230.255.254143.230.255.25565,534
232143.231.0.0/16143.231.0.1 to 143.231.255.254143.231.255.25565,534
233143.232.0.0/16143.232.0.1 to 143.232.255.254143.232.255.25565,534
234143.233.0.0/16143.233.0.1 to 143.233.255.254143.233.255.25565,534
235143.234.0.0/16143.234.0.1 to 143.234.255.254143.234.255.25565,534
236143.235.0.0/16143.235.0.1 to 143.235.255.254143.235.255.25565,534
237143.236.0.0/16143.236.0.1 to 143.236.255.254143.236.255.25565,534
238143.237.0.0/16143.237.0.1 to 143.237.255.254143.237.255.25565,534
239143.238.0.0/16143.238.0.1 to 143.238.255.254143.238.255.25565,534
240143.239.0.0/16143.239.0.1 to 143.239.255.254143.239.255.25565,534
241143.240.0.0/16143.240.0.1 to 143.240.255.254143.240.255.25565,534
242143.241.0.0/16143.241.0.1 to 143.241.255.254143.241.255.25565,534
243143.242.0.0/16143.242.0.1 to 143.242.255.254143.242.255.25565,534
244143.243.0.0/16143.243.0.1 to 143.243.255.254143.243.255.25565,534
245143.244.0.0/16143.244.0.1 to 143.244.255.254143.244.255.25565,534
246143.245.0.0/16143.245.0.1 to 143.245.255.254143.245.255.25565,534
247143.246.0.0/16143.246.0.1 to 143.246.255.254143.246.255.25565,534
248143.247.0.0/16143.247.0.1 to 143.247.255.254143.247.255.25565,534
249143.248.0.0/16143.248.0.1 to 143.248.255.254143.248.255.25565,534
250143.249.0.0/16143.249.0.1 to 143.249.255.254143.249.255.25565,534
251143.250.0.0/16143.250.0.1 to 143.250.255.254143.250.255.25565,534
252143.251.0.0/16143.251.0.1 to 143.251.255.254143.251.255.25565,534
253143.252.0.0/16143.252.0.1 to 143.252.255.254143.252.255.25565,534
254143.253.0.0/16143.253.0.1 to 143.253.255.254143.253.255.25565,534
255143.254.0.0/16143.254.0.1 to 143.254.255.254143.254.255.25565,534
256143.255.0.0/16143.255.0.1 to 143.255.255.254143.255.255.25565,534

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.